Kinetis K22 in QFP144 high-current

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Kinetis K22 in QFP144 high-current

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rev
Contributor III

I've done a number of projects with Kinetis MCUs, but I'm having real trouble with a K22 bring-up.  All boards show a high-current path from VDD to VSS as soon as VDD hits 0.5V.  I've triple-checked schematic pin-out (and PCB) against the datasheet pin out.  There are no parts on the board apart from decoupling capacitors and a couple of pull-up /down resistors.

The only pins tied to GND (apart from VSS, VSSA) are VREFL the dedicated ADC0_DMx pins.

My questions are:

1) Can anyone point me to a reference schematic for the K22 in a LQFP144?

2) I've no-connected COUT33, VREGIN, VBAT, USB0DP/DM.  Are there any special considerations on these or any other pins at power-up?

Any help appreciated.

-- JAG

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rev
Contributor III

Figured it out.. assembly error at my end. The Kinetis device's laser markings are 90deg from "normal" orientation and those were used as visual cue rather than the smaller corner dot.

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120 Views
rev
Contributor III

Figured it out.. assembly error at my end. The Kinetis device's laser markings are 90deg from "normal" orientation and those were used as visual cue rather than the smaller corner dot.

View solution in original post

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